1. Field of the Invention
The present invention pertains to a high pressure fluid intensifier having a power piston connected to the working fluid cylinder member and arranged in concentric telescoping relationship around a stationary working fluid plunger.
2. Background Art
There are numerous applications for high pressure hydraulic fluids requiring relatively large and continuous flow rates at extremely high pressure conditions. One such application is in connection with providing high pressure fluids for fracturing subterranean geologic formations to enhance the recovery of petroleum. Geologic formation fracturing and other oil well stimulation techniques often require the injection of exotic hydraulic fluids, some including entrained abrasives, at pressure up to and exceeding 20,000 psi and in fairly large flow rates. These requirements exceed the practical limits for conventional pumping equipment such as reciprocating plunger pumps or high pressure multi-stage centrifugal pumps.
Accordingly, pumping mechanisms have been developed utilizing hydraulic cylinder or ram actuators for driving the working fluid piston of the so-called fluid end of the pump to produce the high pressure required of the working fluid. By providing a larger diameter piston of the power ram or actuator, this actuator may be operated with power fluid at pressures developed by conventional pumping equipment to produce the high pressure fluid output required of the working fluid pump mechanism. Such devices are conventionally known as intensifiers. Conventional intensifiers are characterized by an arrangement of a power cylinder and piston and a working cylinder and piston arranged end to end with the power piston and working piston rods being common or connected in end to end relationship.
Conventional hydraulic intensifiers have several shortcomings with regard to their use in applications such as those associated with petroleum recovery. The space requirements and weight of conventional intensifiers makes them unattractive for use with the portable equipment for other petroleum recovery operations. The arrangement of the working fluid cylinder chamber, inlet and discharge valving and flow passages has been adapted from conventional pump designs but is not suitable for the higher working pressures required, particularly considering the corrosive and abrasive characteristics of well stimulation and formation fracturing fluids. Moreover, the serviceability of conventional intensifier equipment is generally inadequate and yet must be viewed as an important consideration because of the extreme working conditions to which this type of equipment is subjected. Accordingly, there has been a strongly felt need for improvements in high pressure hydraulic intensifier equipment of the type particularly adapted for use in connection with pumping fluids used to enhance the recovery of petroleum. The advantages of the improved intensifier of the present invention may, however, also be enjoyed in other applications of hydraulic intensifiers.